KAI vs MDY: Correlation
How closely do Kadant Inc (KAI) and SPDR S&P MidCap 400 ETF (MDY) trade together? Their weekly returns over three years give a correlation of 0.66, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are KAI and MDY?
Over the past 3 years, KAI and MDY moved with a correlation of 0.66, which is strong. The relationship has been stable: the 1-year correlation (0.60) sits close to the 3-year figure. Over 5 years the correlation is 0.62, and the annualized covariance of weekly returns is 401.7 %².
In KAI's tracked universe of 14 assets, MDY sits right near the top at #2. Correlation aside, the last 12 months split them widely, with MDY ahead by 27.1 points (-8.8% versus +18.3%). Risk is not evenly split, since KAI carries 2.2 times the volatility of the other side.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
KAI vs MDY: side by side
| KAI (Kadant Inc) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | -8.8% | +18.3% |
| 5-year return | +49.3% | +47.5% |
| Volatility (ann.) | 37.1% | 16.5% |
| Beta vs S&P 500 | 1.34 | 0.91 |
| Max drawdown (3Y) | -41.2% | -24.0% |
| Market cap | $3.6B | – |
| P/E (trailing) | 32.9 | – |
| Dividend yield | 0.46% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
MDY, State Street Investment Management's Mid-Cap Blend fund, carries $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | KAI | MDY |
|---|---|---|
| 2022 | -22.5% | -13.3% |
| 2023 | +58.7% | +16.1% |
| 2024 | +23.6% | +13.6% |
| 2025 | -17.0% | +7.2% |
| 2026 | +7.7% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are KAI and MDY good diversifiers for each other?
Only partially. A correlation of 0.66 means KAI and MDY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between KAI and MDY?
The KAI/MDY correlation stands at 0.66 on a 3-year window (1 year: 0.60, 5 years: 0.62), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for KAI?
Only partially. A correlation of 0.66 means KAI and MDY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.66 mean?
A reading of 0.66 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/kai-vs-mdy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/kai-vs-mdy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: KAI correlations · MDY correlations
